From d63129b5f028646596bd5c57d2832eaf441c77b7 Mon Sep 17 00:00:00 2001
From: Li Lin <linl33@users.noreply.github.com>
Date: Mon, 8 May 2023 16:35:08 +0800
Subject: [PATCH] fix(build): declare moduleSideEffects for
 vite:modulepreload-polyfill (#13099)

---
 .../modulePreloadPolyfill.spec.ts.snap        | 51 ++++++++++++++++++
 .../modulePreloadPolyfill.spec.ts             | 53 +++++++++++++++++++
 .../src/node/plugins/modulePreloadPolyfill.ts |  2 +-
 3 files changed, 105 insertions(+), 1 deletion(-)
 create mode 100644 packages/vite/src/node/__tests__/plugins/modulePreloadPolyfill/__snapshots__/modulePreloadPolyfill.spec.ts.snap
 create mode 100644 packages/vite/src/node/__tests__/plugins/modulePreloadPolyfill/modulePreloadPolyfill.spec.ts

diff --git a/packages/vite/src/node/__tests__/plugins/modulePreloadPolyfill/__snapshots__/modulePreloadPolyfill.spec.ts.snap b/packages/vite/src/node/__tests__/plugins/modulePreloadPolyfill/__snapshots__/modulePreloadPolyfill.spec.ts.snap
new file mode 100644
index 00000000000000..7034be03a7c4db
--- /dev/null
+++ b/packages/vite/src/node/__tests__/plugins/modulePreloadPolyfill/__snapshots__/modulePreloadPolyfill.spec.ts.snap
@@ -0,0 +1,51 @@
+// Vitest Snapshot v1, https://vitest.dev/guide/snapshot.html
+
+exports[`load > doesn't load modulepreload polyfill when format is cjs 1`] = `
+"\\"use strict\\";
+"
+`;
+
+exports[`load > loads modulepreload polyfill 1`] = `
+"(function polyfill() {
+  const relList = document.createElement(\\"link\\").relList;
+  if (relList && relList.supports && relList.supports(\\"modulepreload\\")) {
+    return;
+  }
+  for (const link of document.querySelectorAll('link[rel=\\"modulepreload\\"]')) {
+    processPreload(link);
+  }
+  new MutationObserver((mutations) => {
+    for (const mutation of mutations) {
+      if (mutation.type !== \\"childList\\") {
+        continue;
+      }
+      for (const node of mutation.addedNodes) {
+        if (node.tagName === \\"LINK\\" && node.rel === \\"modulepreload\\")
+          processPreload(node);
+      }
+    }
+  }).observe(document, { childList: true, subtree: true });
+  function getFetchOpts(link) {
+    const fetchOpts = {};
+    if (link.integrity)
+      fetchOpts.integrity = link.integrity;
+    if (link.referrerPolicy)
+      fetchOpts.referrerPolicy = link.referrerPolicy;
+    if (link.crossOrigin === \\"use-credentials\\")
+      fetchOpts.credentials = \\"include\\";
+    else if (link.crossOrigin === \\"anonymous\\")
+      fetchOpts.credentials = \\"omit\\";
+    else
+      fetchOpts.credentials = \\"same-origin\\";
+    return fetchOpts;
+  }
+  function processPreload(link) {
+    if (link.ep)
+      return;
+    link.ep = true;
+    const fetchOpts = getFetchOpts(link);
+    fetch(link.href, fetchOpts);
+  }
+})();
+"
+`;
diff --git a/packages/vite/src/node/__tests__/plugins/modulePreloadPolyfill/modulePreloadPolyfill.spec.ts b/packages/vite/src/node/__tests__/plugins/modulePreloadPolyfill/modulePreloadPolyfill.spec.ts
new file mode 100644
index 00000000000000..3b24fbd5203baa
--- /dev/null
+++ b/packages/vite/src/node/__tests__/plugins/modulePreloadPolyfill/modulePreloadPolyfill.spec.ts
@@ -0,0 +1,53 @@
+import { describe, it } from 'vitest'
+import type { ModuleFormat, RollupOutput } from 'rollup'
+import { build } from '../../../build'
+import { modulePreloadPolyfillId } from '../../../plugins/modulePreloadPolyfill'
+
+const buildProject = ({ format = 'es' as ModuleFormat } = {}) =>
+  build({
+    logLevel: 'silent',
+    build: {
+      write: false,
+      rollupOptions: {
+        input: 'main.js',
+        output: {
+          format,
+        },
+        treeshake: {
+          moduleSideEffects: false,
+        },
+      },
+      minify: false,
+    },
+    plugins: [
+      {
+        name: 'test',
+        resolveId(id) {
+          if (id === 'main.js') {
+            return `\0${id}`
+          }
+        },
+        load(id) {
+          if (id === '\0main.js') {
+            return `import '${modulePreloadPolyfillId}'`
+          }
+        },
+      },
+    ],
+  }) as Promise<RollupOutput>
+
+describe('load', () => {
+  it('loads modulepreload polyfill', async ({ expect }) => {
+    const { output } = await buildProject()
+    expect(output).toHaveLength(1)
+    expect(output[0].code).toMatchSnapshot()
+  })
+
+  it("doesn't load modulepreload polyfill when format is cjs", async ({
+    expect,
+  }) => {
+    const { output } = await buildProject({ format: 'cjs' })
+    expect(output).toHaveLength(1)
+    expect(output[0].code).toMatchSnapshot()
+  })
+})
diff --git a/packages/vite/src/node/plugins/modulePreloadPolyfill.ts b/packages/vite/src/node/plugins/modulePreloadPolyfill.ts
index 0f1ef11cf26f5e..ede79c8b882f77 100644
--- a/packages/vite/src/node/plugins/modulePreloadPolyfill.ts
+++ b/packages/vite/src/node/plugins/modulePreloadPolyfill.ts
@@ -25,7 +25,7 @@ export function modulePreloadPolyfillPlugin(config: ResolvedConfig): Plugin {
         if (!polyfillString) {
           polyfillString = `${isModernFlag}&&(${polyfill.toString()}());`
         }
-        return polyfillString
+        return { code: polyfillString, moduleSideEffects: true }
       }
     },
   }